RU2609224C1 - Explosive marking method - Google Patents

Abstract

FIELD: blasting operations.

SUBSTANCE: invention relates to chemical methods of inspecting explosive substances and forensic identification preparations. Explosive marking method is introducing marking composition which contain identifiers in explosive material, the number of identifiers is equal to number of technical parameters subjected to marking. Mixture of polyorganosyloxanes with different molecular chain lengths is used as the identifiers, in each molecular chain each technical indicator matches an identifier in the form of a polyorganosiloxane with a corresponding molecular chain length and corresponding "exit time" (“retention”) on a chromatogram.

EFFECT: so in the composition of explosive element there is formed "chemical bar code", reading of which is carried out on chromatogram on the principle of presence or absence of component at the specified value of time of its "exit" (“retention”).

1 cl, 4 dwg, 1 tbl

Description

The invention relates to chemical methods for the examination of explosives (BB) and forensic identification drugs and can be used in operational investigative, investigative, forensic and judicial practice.

Investigations of various kinds of circumstances made using explosives (explosives) require not only establishing the type of explosive device and explosives used, but also establishing the manufacturer of this explosive, as well as tracking its path from the manufacturer to the place of use, or illegal traffic. Investigations into the circumstances of industrial accidents involving explosives, as a rule, require the establishment of a date for the manufacture and loading of wells (holes) in order to further investigate compliance with the manufacturing technology of explosives and their loading. In a number of mining enterprises, blasting operations use industrial explosives (including emulsion explosives), supplied directly from several manufacturers. Often, the prepared unit can be charged with several types of explosives at once from several manufacturers. This makes it difficult to identify the causes of possible failures, and also makes it impossible to uniquely identify the manufacturer and type of explosives in the failed well. In addition, there is the problem of identifying accidentally lost explosives when they are detected.

To solve these issues, various methods of marking explosives are used that are technically different.

For example, a method for marking explosives is known, including introducing into the explosive a marking composition containing identifiers, the number of which is equal to the number of technical indicators to be labeled, identifiers having oil and fat solubility, chemical resistance in media with any pH range, and resistance to free radicals are introduced chemical inertness to the components of the explosive, the lack of properties of surface-active substances of the first kind, chemical inertness the explosion products and the absence of toxic properties, are used as identifiers polydimethylsiloxanes (PMS) or polyethylsiloxanes (PES) or a mixture thereof (RU №2368591, S06V 23/00, G01N 33/22 publ. 27.09.2009).

In the known method for the manufacture of emulsion explosives use surface-active substances (surfactants) of the 2nd kind (when creating reverse, or "invert" emulsions). If the identifiers possess the properties of a surfactant of the first kind, their introduction into the emulsion will destroy it. For this reason, the sign of the absence of the properties of surfactants of the first kind is also significant - polymethylsiloxanes and polyethylsiloxanes do not have surfactant properties. After the explosion, new chemicals are obtained from the components of the explosive with which the identifiers should not react, i.e. they must be chemically inert to explosion products. Polymethylsiloxanes and polyethylsiloxanes are chemically inert to explosion products.

However, as a result of the studies, it was found that this method has some drawbacks that, in some circumstances, can lead to inaccurate or unreliable identification of explosives, and often to its technical impossibility in practice:

- during the explosion of an explosive charge, marked by the method proposed by the prototype, the polymer chains of the markers are partially disintegrated - new compounds with shorter polymer chains can form. The newly formed short polymers may be analogous to the markers of another manufacturer of another explosive. The results of the analysis will be mixed - as traces of markers of several manufacturers and / or several explosives at once will be detected;

- it is possible to technically detect these markers on such important carrier objects as “the surfaces of the hands of a suspected person”, using existing and promising research methods, since mixtures of polymethylsiloxanes (PMS) and polyethylsiloxanes (PES) are oil-soluble and will be retained for a long time in the sweat layer of the human skin, but there may be errors due to the prevalence of these compounds (for example, PES - in cosmetics: lipstick), which again leads to the loss of the most important “crime” listicheski relevant information ";

- the use of a mixture of polymethylsiloxanes (PMS) and polyethylsiloxanes (PES) is a significant drawback, since PES, in contrast to PMS, have significantly less "thermodynamic stability" and will more strongly "disintegrate" and interact with explosion products;

- the use of this method of encoding information has in practice considerable complexity and high cost, since it requires expensive instrumentation (gel permeation chromatography) and sufficiently sophisticated techniques to evaluate the results.

The present invention is aimed at achieving a technical result, which consists in increasing the reliability of identification of explosives by its identification code while simplifying the process of identifying and determining this code.

The specified technical result is achieved by the fact that in the method of marking an explosive, which consists in introducing into the explosive a marking composition containing identifiers, the number of which is equal to the number of technical indicators to be marked, while the identifiers use a mixture of polyorganosiloxanes with different and different from each other molecular chain lengths, in which each one technical indicator corresponds to an identifier in the form of polyorganosiloxane with the corresponding the corresponding length of the molecular chain and the corresponding time of exit ("retention") on the chromatogram.

These features are significant and are interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

Figure 1 presents the chromatogram of the polydimethylsiloxane liquid "Dow Corning @ 200" - "RMX-200/20" (the index "20" in the name indicates the viscosity in centistokes).

Figure 2 shows the principle of forming a "chemical barcode" in a binary system,

figure 3 shows the chromatogram of the "individual marker" polydimethylsiloxane fluid "Dow Corning @ 200" - "RMX-200/2" (undecomethylpentasiloxane);

figure 4 shows the characteristic mass spectrum of "Dow Corning @ 200" - "RMX-200/2" - undecomethylpentasiloxane detected in products upon the explosion.

According to the present invention, a new method for marking an explosive is considered, which is based on introducing into the explosive a marking composition containing identifiers, the number of which is equal to the number of technical indicators to be marked.

In this case, a mixture of polyorganosiloxanes (oligoorganosiloxanes) with various molecular chain lengths is used as identifiers, in which each one technical indicator corresponds to an “identifier” in the form of polyorganosiloxane (oligoorganosiloxane) with the corresponding molecular chain length and the corresponding exit (retention) time on the chromatogram. corresponding to this length of the molecular chain.

The main classes of branched, cycloline-linear, and ladder polyorganosiloxanes that can be used as “identifier markers” include polymethylsiloxanes, polydimethylsiloxanes, polyphenylsiloxanes, oligodimethylphenylsiloxanes and polymethylphenylsiloxanes, some silicon and other C4 and C6 alkyl radicals connections.

To illustrate the thermodynamic stability of polyorganosiloxanes, Table 1 shows some typical physicochemical properties of some of the Dow Corning @ 200 polydimethylsiloxane fluids used in the tests as prototype markers, according to the manufacturer: source: http: www / sgrus. ru.

Table 1 No. Viscosity at 25 ° C (mm / s-centistokes), according to STM 0004. Flash point, ° C (closed crucible), according to STM 0021. Flash point, ° C (open crucible), according to STM 0006. Volatility,% (max.) Weight loss after 24 hours at 150 ° C, according to STM 208. one. 10 > 100 > 163 10.0 2. twenty > 100 > 204 10.0 3. fifty > 100 > 285 2.0 four. one hundred > 100 > 315 0.5 5. 200 > 100 > 315 0.5 6. 350 > 100 > 315 0.5 7. 1000 > 100 > 321 0.5 8. 10,000 > 100 > 321 2.0

Further experimental tests of the charges of individual “powerful” blasting explosives, mixed ammonium nitrate explosives, as well as industrial water-filled explosives of various weights, to which Dow Corning @ 200 polydimethylsiloxane fluids were added as “prototype markers”, in amounts of about 200 g per 1 ton of explosives (0.02% wt.) and less, showed the following:

- polydimethylsiloxanes are “well detected” and separated by GLC and HPLC “upon the explosion”, including against the background of existing contaminants with “foreign substances” (for example, petroleum products);

- no traces of products of polydimethylsiloxane liquids on lighter homologues were found, which indicates the absence of transfer of decomposition products and thermal degradation of polydimethylsiloxane to washouts after the explosion.

To illustrate the foregoing, Fig. 3 shows the chromatogram of the “individual marker” of the Dow Corning @ 200 - RMX-200/2 polydimethylsiloxane liquid (undecomethylpentasiloxane), and Fig. 4 shows the characteristic Dow Corning @ 200 mass spectrum - "RMX-200/2" -undecomethylpentasiloxane found in products after an explosion.

Thus, a “chemical barcode” is formed in the composition of the explosive, the reading of which is carried out according to the principle of the presence or absence of a component with the corresponding exit time (“retention”) in the chromatogram.

Using as markers of explosives only a mixture (“set”) of polyorganosiloxanes (oligoorganosiloxanes) with a strictly defined length of molecules of each of the components included in this mixture allows one to determine the presence and decipher the marking code in one step, using two criteria as coding data: / the absence of a substance according to the principle of binary code (0/1) and the time of their release on the chromatogram. Research methods used in decoding: - gas-liquid chromatography (GLC); High performance liquid chromatography (HPLC); - chromatography-mass spectrometry "for selected ions."

It is possible to mark in this way not only the mixed and individual explosives themselves, but also their components - inorganic oxidizing agents (ammonium nitrate of brands “A”, “B” and “6ZhV”).

The marking according to this method is similar to marking according to the type of barcode and therefore can be considered as a "chemical barcode" (figure 2). We encode the information: 4120111231 (41 - plant, 2011 - year. 12 - month, 31 - date of manufacture of the batch of explosives). In binary, this will be 10011100110100111010111111 or the same for significant digits 10_0111_0011_0100_1110_1011_1111. It is easy to show that 1 is the presence of a substance (PMS) in the chromatogram, 0 is its absence, at a strictly defined exit time t. The exit time t on the chromatogram is a complete analogue of the “distance between dashes and their thickness” on the “classic barcode”. Since the peaks of the coding substances will correspond to polyorganosiloxanes that are identical in structure but differ in the length of the polymer molecule (molecular chain), the time of “exit” (“retention”) in the chromatogram is a strict function of the length of the polyorganosiloxane molecule.

The advantages of the proposed method for marking explosives:

- polyorganosiloxanes (oligoorganosiloxanes) are extremely thermodynamically stable, do not decompose upon storage by microorganisms, and are also completely inert and non-toxic to humans and animals (for example, “silicone implants in plastic surgery”);

- polyorganosiloxanes (oligoorganosiloxanes) are exceptionally cheap;

- their introduction in an amount of 200 g per 1 ton of explosives (0.02% wt.) will not lead to a rise in price of explosives or to a change in explosive properties;

-polyorganosiloxanes (oligoorganosiloxanes) will be soluble in the sweat layers of human skin, will be stored there much longer than traces of trace amounts of explosives, which will allow not only the fact of the presence of traces of explosives to be detected in washouts from the surfaces of the hands of suspected persons, but also establish the fact of treatment (“contact ») Them, with specific lots of explosives or products containing them;

- similarly, it will be possible to receive such information after the explosion;

- organopolysiloxanes (oligorganosiloxanes) can mark not only individual explosives, but also components — inorganic oxidants of mixed explosives (ammonium nitrate, for example), which will completely “remove” the extremely important question for forensic experts on “its origin in the traces after an explosion” ( “Biological origin or not”).

This method also allows you to avoid getting the wrong result of “reading the chemical barcode” when mixing two different batches of explosives, it is insensitive to the interaction of markers with explosion products, marking compounds themselves cannot be completely removed by any physicochemical methods from the explosives, and also due to the features of the marking algorithm and reading information, avoids "errors in its decoding" in case of ingestion of polyorganosiloxanes (oligoorganosiloxanes) of "household use".

Claims (1)

A method of marking an explosive, which consists in introducing into a explosive a marking composition containing identifiers, the number of which is equal to the number of technical indicators to be marked, characterized in that the identifiers use a mixture of polyorganosiloxanes with different lengths of molecular chains, in which each technical indicator corresponds to identifier in the form of a polyorganosiloxane with an appropriate molecular chain length and corresponding time output on the chromatogram.

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